Noise-muffler.



J. F. DODGE.

NOISE MUFFLER.

APPLICATION FILED AUG.2I. 1915.

' 1,184,431. Patented May 23,1916.

UNITED STATES PATENT OFFICE.

JOHN F. DODGE, OF DETROIT, MICHIGAN, ASSIGNOR TO DODGE BROTHERS, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

NOISE-MUFFLER.

Specification of Letters Patent.

Patented May 23, 1916.

Application filed August 21, 1915. Serial No. 46,735.

7 noise mufflers especially adapted for use as exhaust mufilers for gas engines.

Another object of the invention is to provide a muffler which will satisfactorily silence the noise of the exhaust without producing an objectionably high back pressure and which muflier, being preferably of a knock-down construction, can be adjusted in dimensions proportionate to the requirements, without obtaining an objectionably high back pressure.

Other objects of the invention are to provide a knock-down mufiler from which the deposited carbon may be readily cleaned out by taking the muffler apart.

- The above are some of the objects of the invention and others will be apparent from the specification and drawings.

The invention consists of suitable features of construction and combinations of parts to be hereinafter described and then claimed with reference to the accompanying drawings illustrating a desirable embodiment of the invention and in which- Figure 1 is a longitudinal central section; Fig. 2 is an end elevation as viewed from the right of Fig. 1; Fig. 3 is a transverse section on line 33, Fig.- 1, as viewed in the direction of the arrow, showing one of the noise silencers; Fig. 4 is a transverse section on line 4.-4 of Fig. 1, as viewed in the direction of the arrow, showing another noise silencer of the mufiler and which is associated with that shown in Fig. 3; and Fig. 5 is an enlarged detail section on the line 55 Fig. 4:-

Referring. to Fig. 1, the casing of the muffier is shown as composed of sections 10, 11, 12 and 13, there being as many sections 11, 12 as desired. The sections 10 and 13 constitute the-ends or heads of the mufller and the former is provided with an inlet neck 14, I

while the latter is provided with an outlet neck 15. With the exception of the through bolts 16 and their nuts, the mulfier is preferably composed of sheet steel stampings. Preferably there are three bolts 16 to prevent buckling, and the heads of the bolts and the nuts thereof are positioned upon raised seats 17, 18 on said heads or ends. The sections such as 11 are more fully shown in Fig. 4. and are stamped up so as toform cup-shaped members provided with a wall 19 and a wall 20 of less diameter so that the reduced portion at 20 may be slid into the end or head 10, as shown in Fig. 1. Within the wall 20 the section 11 has a conical portion 21, the

base portion of which just within the wall 20 is provided with an annular series of openings 22 which are formed by striking up portions of the metal in order to provide hoods or deflectors 23 which are inclined toward said wall and provided at their inner ends with openings 23. Said hoods preferably extend in a direction radial of the conical portion 21.

As shown more clearly in Fig. 3, section 12 is provided with an annular wall 24 and a wall 25 of reduced diameter so as to provide a reduced portion which may be slid into the section 11. Said section 12 is furthermore provided with a conical portion '26 which has an enlarged central opening 27. Said conical portion 26 is preferably continuously tapered from its outer periphery to its central aperture, but on a gradual inward curve toward its axis. Section 12 is also preferably stamped up into cup shape.

A second section 11 is then slid into the secsection 11, and so on, so that the said sections are nested or telescoped together to any desired length through the medium of slip-joint connections. It will therefore be seen that the sections 11 alternate with sections 12, while the sections 12 are located between them so as to alternate with sections 11. It will also be seen that the conical portions 21 of the sections 11 extend toward the end 10, and that the conical portions 26 of sections 12 extend toward the end 13 and said conical portions are thus successively reversed, while the conical portions '21 will be seen to have openings or apertures 22 which are located around the apices of said larger at the middle and larger at their outer portions.

By the described construction of mufiier the desired course is given to the exhaust gases, as there will be imparted thereto a twisting action or an action such that there is a lateral expansion and contraction of said gases. The gases passing into the mufiier are first deflected outwardly through the openings 22, after which the gases impinge upon the wall of the casing and are deflected back against the adjacent wall of the conical portion 26, from whence the gases issue through the opening 27, this action of lateral expansion and contraction alternating throughout the muffler. The repeated expansion and concentration of the gases and the reversal of their courses through" the mufiler supply the desired silencing or mufiiing effect, the number. of reversals to" accomplish tliis purpose being brought about by varying the number of the sections 11, 12, which are placed in series throughout the muflier. The size of the openings 22 at the circumference of the first conical portion 21 and also their shape afl'ects the mufiling action. If these openings are made too large in area as compared with the area of the inlet of the mufller, more sections are necessary to produce the muffling effect. If these apertures are made too small the back pressure on the motor is greatly increased. Consequently the size,

' shape and number of openings in the conical portion 21 of the first section 11 is important. It is believed that there is something of an injector effect in the alternate concentration and diffusion of the gases,

' and if this takes place to any extent it will aid in reducing the back pressure on the motor to a low point. Numerous other advantages not necessary to be recited are also present'in the particular structure shown.

Obviously the invention is susceptible of modification, as parts may be, .p'mitted, added and substituted without departing from the spirit and scope thereof as expressed in the claims.

What I claim as new is 1. A noise mufiier comprising, in combination, a series of separate casingsections connected by slip joints, open cones, one integral with each of said sections, said cones being alternately presented toward opposite ends of said muflier, whereby successive chambers are provided which, alternately, are larger at the middle thereof and larger at their outer portions, alternate ones of said cones having their openings outward from the axis of said muffler and the intermediate cones having their openings along said axis, and hoods over the said outward openings, said hoods being inclined to the walls of said casing sections so as to direct the gases toward said walls.

2. A noise mufiler comprising, in combination, open end caps or heads, intermediately thereof a series of separate casing sections connected by slip joints, open cones, one integral with each of said sections, said cones being alternately presented toward opposite ends of said mufiler, whereby successive chambers are provided which, alternately, are. larger at the middle thereof and larger at their outer portions, alternate ones of said cones having their f(fipenings outward from the axis of said mu er and the intermediate cones having their openings alon said axis, and hoods over the said outwar openings, said hoods being inclined to the walls' of said casing sections so as to direct the gases toward said walls, and through bolts passing through said caps or heads and said cones, whereby the parts are united.

Signed at Detroit, Michigan, this 16th Witnesses A. A. MCPHERSON, A. H. KNIGHT. 

